Be careful with the default smearing method (ISMEAR=1): Difference between revisions

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and use a small width {{TAG|SIGMA}}=0.05 (do not make SIGMA too small,
and use a small width {{TAG|SIGMA}}=0.05 (do not make SIGMA too small,
values below 0.001 can also lead to undesirable symmetry breaking).
values below 0.001 can also lead to undesirable symmetry breaking).
Read more on this in {{TAG|Number of k points and method for smearing}}!




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[[Category:Calculational issues]]
[[Category:Calculational issues]]

Revision as of 11:29, 14 October 2020

The default for ISMEAR is 1 in VASP. This setting is not appropriate for insulators and semiconductors, and can results in one-electron occupancies that are larger than 1 (2 for non spinpolarized) systems, and conversely some states being occupied by less than 1 electron close to the Fermi-level. It is strongly recommended to set ISMEAR=0 in the INCAR file and use a small width SIGMA=0.05 (do not make SIGMA too small, values below 0.001 can also lead to undesirable symmetry breaking).

Read more on this in Number of k points and method for smearing!